3 Questions About NASA's New Heavy-Lift Rocket Plan

In NASA's last budget, Congress mandates that the agency build a new heavy-lift launch system to take the place of the retiring space shuttles and the canceled Constellation program, one capable of taking astronauts into orbit and far beyond. Now the first steps of NASA's plan have been released, but PM contributor Rand Simberg says this proposal's complexity and politically driven makeup could mean that it will never produce a flyable vehicle.

With the space shuttle program set for retirement, there's no way for NASA to send astronauts into Earth orbit anytime soon other than booking rides with the Russians at tens of millions of dollars per seat. Congress allowed NASA to start to use the burgeoning private space industry for crew transport to the International Space Station, but it mandated that NASA develop its own heavy-lift rocket system capable of going there, to the moon or beyond to drive human spaceflight in the long term. Last week, the big new plan took its first small steps as NASA administrator Charles Bolden announced NASA's proposal.

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What is it?

Dubbed the Space Launch System (SLS), the NASA plan's origin lies in two places: the congressional mandate to come up with some kind of heavy-lift system, and the ruins of the heavy-lift Ares V rocket. Ares V was the key piece of the Constellation program that began under President George W. Bush as NASA's plan for its next heavy-lift system to go to the moon and Mars, before President Obama canceled the program last year.

Under the new proposal, SLS will, at least at first, be derived from space shuttle components. The main first stage will use the remaining liquid oxygen (LOX)/hydrogen space shuttle main engines (SSMEs, also known as the RS-24). However, because there are only 15 of these shuttle engines left, this will only work for three flights. (The new launch system will need five at a time, and unlike shuttle flights, the engines won't be recoverable.) Once these engines are used up, the system will switch over to a cheaper expendable engine, yet to be developed by Pratt & Whitney Rocketdyne, called the RS-25E.

The booster stage will use two of the five-segment solid-rocket boosters (SRBs) planned for use as the first stage of the now-canceled Ares I. The second stage will also use LOX/hydrogen propellants, and burn them with the new J-2X engine that was being developed for the second stage of the Ares launchers. It is a modern version of the venerable J-2 used in the upper stages of the Saturn V in the 1960s, and is scheduled to be test-fired this week at NASA's Stennis Space Center in Mississippi.

The reason behind this jumble of leftover parts and new technologies is primarily politics. Congress mandated using existing contracts and contractors as much as possible—that means using space shuttle infrastructure and preserving jobs that would otherwise be lost with the end of the shuttle program. To that end, Congress also stated which contractors would build it without having to even bid.

So the good news is, NASA now has its plan. But here's the bad news: That plan could become an expensive, convoluted mess that never actually produces a flyable vehicle.

Where to?

Beyond Congress's (unfunded) mandate that NASA create its own new heavy vehicle to carry astronauts to space, the SLS goals are totally uncharted. The vehicle would be similar in performance to the Saturn V rocket that delivered the Apollo missions to the moon in the 1960s, but it has no defined mission or target. Nor has anyone planned a budget for payloads.

Even the specs of the system seem to be confusing: The vehicle is supposed to be capable of delivering 130 tons of payload to low Earth orbit. The legislation indicates U.S. tons (2000 pounds), but NASA's responses to Congress have been couched in metric tons (2200 pounds). It matters, because a 10 percent difference in payload requires a much larger difference in weight of the fueled vehicle on the launch pad, and an even greater difference in development and operational costs.

Why now?

NASA watchers may have noticed that the basic plan now in place is essentially the same thing that's been in the works since January. What's new—and what may have pushed NASA to put out an official proposal this month—is the about-face of Sen. Richard Shelby of Alabama (home of NASA Marshall Space Flight Center in Huntsville), ranking member of the NASA appropriation committee. After previously insisting that NASA's new heavy-lift system use the existing solid-booster design developed for Ares, Shelby sent a letter to the NASA administrator released last week calling for competitive bidding for the booster contract, arguing that competition would drive down costs. It probably didn't hurt that Aerojet and Teledyne Brown Engineering recently teamed up to build new liquid motors in Huntsville, offering an opportunity to bring NASA contracts to Alabama. The Aerojet motors, designated the AJ-26, will be based on an old Soviet design, the NK-33, and offer almost 400,000 pounds of thrust at sea level, allowing them to compete with the powerful SRBs.

The problem is, though, that it seems this competition will occur only after the first few flights of the vehicle, once the SRBs are used up. That could prove troublesome down the road. Using the SRBs for the first few flights would mean all of the launch facilities would have to be built to move a very heavy vehicle from the Vehicle Assembly Building to the launchpad, and do it on an old crawler and crawl-way that probably need an upgrade (Apollo's Saturn was much lighter, being fueled at the pad). Never mind that Congress still hasn't authorized, let alone appropriated, the money to build a vehicle with so many developmental twists and turns.

Ultimately, jobs—and not actual progress in space—seem to be the driving force of the program. Even if it never actually flies, SLS may still meet its primary mission requirement: delivering federal funding to the states and districts of those in Congress with a particular interest in NASA's budget. Whether that's the best thing for U.S. space policy is another story.